An Integrated Review of Developmental Outcomes and Late-Preterm Birth

Objective: To evaluate existing evidence on long-term developmental outcomes of late-preterm infants (LPI; infants born 34-36 6/7 weeks gestation). Data Sources: Computerized bibliographic databases and hand search for English language articles published between January 1995 and November 2010 yielded 817 articles. Study Selection: Twelve studies (10 cohort and two cross-sectional) were identified that defined late-preterm (LP) birth as 34 to 36 6/7 weeks gestation and addressed growth and neurodevelopmental outcomes in LPI. Data Extraction: Using a modified Downs and Black scale for assessing the quality of experimental and observational studies, two reviewers who were blind to each other's ratings assessed study quality. Ratings ranged from 12.5 to 14 with moderate to very good interrater agreement. Kappa (κ) values were 0.83 (reporting), 0.63 (external validity), 0.73 (internal validity), and 0.83 (design) for the four subscales and 0.56 for the whole scale, with no major systematic disagreements between reviewers. Data Synthesis: Studies were divided into five categories to include the following developmental outcomes: neurodevelopment, behavioral, cognitive, growth, and function. Using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines, synthesis of the findings is provided as an integrative review. Conclusion: Significant variations in study populations, methodology, and definition of LP exist. Due to paucity and heterogeneity of the existing data especially in infants born 34 to 36 6/7 weeks, there is no clear characterization of the long-term risks, and future research is needed.